What is Test Driven Development?

Essentially, test driven development means that the code is written after the tests... when the test suite is working, its prety likely that the program is too!

Test Driven software development tends to result in programs that are easier to test, and easier to change, than programs written using other methods, as the test cases are always there to help catch changes that have unforeseen side-effects.

A Simple Example of Test Driven Design

Test Driven Resources

http://www.agiledata.org/essays/tdd.html